Feeding device



April 9,1940. E. WHITEHEAD FEEDING DEVICE Filed Jan. 7. 1939 IN N 20R.

ATTORNEYS Patented Apr. 9, 1940 V UNITED STATES,

2,196,240 FEEDING DEVICE Edward WhiteheadLSimcoe, Ontario, Canada, as-

signor to American Can Company, New York,

N. Y., acorporationof Application January 7,

Claims.

The present invention relates to a feeding device for sheet material and the like and has particular reference to an improved feed dog used ina feeding device on a sheet metal punch press 5 or the like machine.

In the can making industry many parts of containers or cans are formed in punch presses from tin plate or the like in sheet or strip form. The sheet or strip is usually fed into the press .by a feeding device having one or more feed dogs. When feeding some poorer grades of plate such as that which has a very thin edge, considerable difiiculty has been experiencedin proper feeding of the plate at high speeds into the press. The feed dogs easily deform the thin .edge of the plate and thus improperly register it under the press die. -The instant invention contemplates. overcoming this difficulty by providing a feed dogwhich will curve thefed sheet into an arch form while thereby stiffen it against 'defeeding it and formation.

An object therefore, of the inventionis the provision in a punch press or .the like, of a feed- 4 ing device, having feed dogs for advancing the sheet material into and through the press, wherein the feed dogs are formed with .a .curved feeding lip which engages a sheet to be fed and curves it into arch form thus stiffening the'sheet so that deformation of its feeding edge and the resultant improper registration in the'press will be prevented.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawing, discloses a preferred embodiment thereof.

Referring to the drawing: Figure 1 is a perspective view of an important part of a press feeding device embodying the instant invention, parts being broken away;

' Fig. 2 is an enlarged side elevation of one of the feed dogs used in the feeding device, with parts broken away;

Fig. 3 is a top plan view of the parts shown in Fig. 2; and I I Fig. 4 is a front elevation and section of the same parts, the view also showing a portion of 50 a sheet of. material in position to be fed.

As a preferred embodiment of the invention the drawing illustrates the principal parts of a feeding device used in connection with a punch press for-forming can parts from a strip of tin plate A or the like sheet material. The strip is New Jersey I 1939, SerialNo. 249,809

preferably fed by advancing it in a step-byestep movement through the feeding device.

While being advanced, the strip A is supported partially on a bed It and partially on a guide rail l2 which is mounted on the bed along one side thereon The guide rail is formed with a longitudinal shoulder l3 which guides one edge of the strip and thus keeps it traveling in a straight line. The opposite edge of the strip is guided by a shoulder l5 which depends from a 10 cover plate l6 secured on top of the guide rail 12. The shoulder l5 rests'on top of the bed. H so that the main body of .the cover plate is in spaced relation to the bed.

To prevent overfeeding of the strip as it is 135 advanced through the feeding device a yieldable friction drag element is provided which engages on top of the strip. This drag element includes a spring barrel. l3 disposed in a vertical bore IS in a boss 2| formed on the cover plate l6. .A 20 compression spring 22 also disposed in the bore exerts its pressure againstthe spring barrel and thus presses the latter against the strip A. g

Feeding of the strip A through the feeding deviceina step-by-step movement is preferably 25 effected by a plurality of spaced feed dogs 25 which are mounted on pivot pins 26 secured in a side of a slide bar 21 having sliding movement in a groove 28 formed in the bed H. The inner edge of the guide plate I2 preferably extends 30 over the top of a portion of the slide bar and hence retains the latter in its sliding position within its groove.

The slide bar 21 is reciprocated in its groove, first on a forward or strip feeding stroke and 35 thence on a backward or return stroke, by any suitable means operating in time with the moving parts of the press. For this purpose there is provided a link 3i the operating end of which is connected by a pivot pin 32 to a lug 33 which depends from the outer end of the slide bar 21.

Each feed dog 25 includes a main body memher or portion 35 which is backed up by a solid stop lug 36 formed on. a spring block 31 secured to the slide bar 21. The dog engages the stop lug above its pivot pin 26, the top surface of the lug and the dog being flush and preferably inclined toward the front of the dog.

The dog 25 is yieldably held against the stop lug by a compression spring 38 which is disposed in abore 39 formed in the spring block and also in a boss M formed on the block. One end of the spring presses against the feed dog at a point below its pivot pin 26. The opposite end of the spring surrounds a shouldered end of a spring compression adjusting screw 42 which is threaded into the end of the spring boss 4|.

The body member 35 of each feed dog 25 is provided with an enlarged head 44 which extends above the slide bar 2'! and into the path of travel of the strip A being fed. The forward edge of the head is formed with a sloping upper lip 45 which is undercut with a curved strip engaging groove 46 (Fig. l). Below this groove the edge of the head curves outwardly and downwardly in a lower guide lip 41. It is to this head and the curved groove 46 that the invention is particularly directed.

When the slide bar 21 moves on a forward stroke the rear end of the strip A is engaged by the lower curved lip ll of a feed dog head 44 and rides up along the lip. This action slightly lifts the strip at a point approximately in the middle of the strip edge. The strip edge thus assumes a transversely curved or arch shape and in this condition it enters the curved groove 46 of the head. The groove 2-6 maintains the strip edge in this curved or flexed condition while advancing the strip through one step of the slide bar. On the backward stroke of the slide bar the drag element It holds the advanced strip stationary while the bar moves back far enough to bring the next feed dog into position ready for advancing the strip through another step.

Thus as each feed dog 25 comes into position in back of the strip to advance it through one step, the curved lower lip 51 of the dog head 44 curves the strip edge into arch shape and thereby stifiens it before it is engaged by the curved groove 46. The strip edge is thereby prevented from being distorted with the result that the strip is properly presented to the press or other machine to which the feeding device is attached.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

I claim:

1. A feed dog for a strip feeding device and the like, comprising in combination a body memher and a strip engaging head on said body member, said head having a curved groove disposed at its forward sheet engaging surface for receiving therein an edge of the strip to be fed and for holding said edge in an arch form thereby stiffening the strip so that deformation of its feeding edge will be prevented.

2. A feed dog for a strip feeding device and the like, comprising in combination a body memher, a strip engaging head on said body member and a beveled upper lip on said head, said lip having an undercut curved groove disposed at its forward sheet engaging surface for receiving therein an edge of the strip to be fed and for holding said edge in flexed position thereby stiffening the strip so that deformation of its feeding edge will be prevented.

3. A feed dog for a strip feeding device and the like, comprising in combination a body member, a strip engaging head on said body member, said head having a curved groove formed therein, and a lower curved lip merging into said groove, said lower lip being adapted to engage and lift the feeding edge of a strip to be fed and to guide said edge into said groove, said groove receiving and maintaining said edge in an arch form thereby stiffening the strip so that deformation of its feeding edge will be prevented.

4. In a strip feeding device, the combination of a bed for supporting a strip to be fed, guide rails on said bed for maintaining the strip in a predetermined path of travel, a cover plate extended over the path of travel of the strip, a reciprocable slide bar in said bed, a feed dog on said slide bar, said feed dog having a curved groove formed therein for engaging an edge of the strip to be fed and for holding said edge in an arch form thereby stiffening the strip so that deformation of its feeding edge will be prevented, and a yieldable drag element disposed in said cover plate and frictionally engaging said strip for preventing over-feeding of said strip by said feed dog.

5. In a strip feeding device, the combination of a bed for supporting a strip to be fed, guide rails on said bed for maintaining the strip in a predetermined path of travel, a cover plate extended over the path of travel of the strip, a reciprocable slide bar in said bed, a feed dog pivoted on said slide bar, said feed dog having a curved groove formed therein for engaging an edge of the strip to be fed and for holding said edge in an arch form thereby stiffening the strip so that deformation of its feeding edge will be prevented, a stop block secured to said slide bar adjacent said feed dog, a stop formed on said stop block for backing up said feed dog when the latter is in strip engaged position, and a yieldable pressure element in said stop block and engaging against said feed dog, said pressure element pressing the dog against its stop and also permitting rocking movement of the dog relative to the slide bar.

EDWARD WI-HTEHEAD. 

